Wideband retroreflector

• US 7,383,026 B1
• Filed: 10/17/2005
• Issued: 06/03/2008
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: National Security Agency
• Original Assignee: The United States of America As Represented By The Director National Security Agency
• Inventors: Detch, John Lewis, Schwartz, Hugh Warren
• Primary Examiner(s): Le; Thanh C
• Application Number:
  US11/254,119
• Time in Patent Office: 960 Days
• Field of Search: None
• US Class Current: 455/106
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 3/2647 Retrodirective arrays

Abstract

A novel single wideband retroreflector is disclosed that eliminates the need for a local oscillator and a local transmitter. The wideband retroreflector of the present invention comprises an antenna, a circulator, and a mixer. An externally produced continuous wave radio wave transmission within the microwave-millimeter wave frequency band is modulated with a wideband signal with a minimum operating instantaneous bandwidth of 5 KHz-500 MHz and retransmitted as a modulated waveform by the antenna.

Claims

1. A wideband mixer-circulator retroreflector circuit, comprising:

a) an antenna, said antenna having an output;

b) a circulator, said circulator having a first port, a second port, and a third port, said first port electrically connected to the output of said antenna; and

c) a mixer, said mixer having a first input, a second input, and an output, said first input electrically connected to the second port of said circulator, said second input electrically connected to a user-definable input signal, and said output electrically connected to the third port of said circulator.

2. The device of claim 1, further comprising an amplifier, said amplifier having an input and an output, said input electrically connected to the second input of said circulator, and said output connected to said first input of said mixer.

3. The device of claim 2, wherein said retroreflector antenna receives a signal in the range of the mixer and circulator frequency response.

4. The device of claim 3, wherein said retroreflector antenna receives a signal in the range of 1 GHz to 4 GHz.

5. The device of claim 4, wherein said user-definable input signal is a wideband signal with a minimum instantaneous bandwidth of 5 KHz to 500 MHz.

6. The device of claim 5, wherein said user-definable input signal modulates said signal to produce a modulated signal, said antenna retransmitting the modulated signal.

7. The device of claim 1, wherein said retroreflector antenna receives a signal in the range of the mixer and circulator frequency response.

8. The device of claim 1, wherein said retroreflector antenna receives a signal in the range of 1 GHz to 4 GHz.

9. The device of claim 1, wherein said user-definable input signal is a wideband signal with a minimum instantaneous bandwidth of 5 KHz to 500 MHz.

10. The device of claim 1, wherein said user-definable input signal modulates said signal to produce a modulated signal, said antenna retransmitting the modulated signal.